i want to costumize rich:accordion with itemRightIconInactive="chevronUp" and itemRightIconActive="chevronDown"

this is my facelet :

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<ui:composition xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:a4j="http://richfaces.org/a4j"
xmlns:rich="http://richfaces.org/rich">
<h:head> </h:head>
<h:body>
<h:form>
<rich:panel style="width:500px" header="Using rich:accordion">
<rich:accordion itemRightIconInactive="chevronUp"
itemRightIconActive="chevronDown" itemRightIconDisabled="grid">
<rich:accordionItem>
<f:facet name="header">
<h:panelGrid columns="2">
<h:outputText value="New York City" />
</h:panelGrid>
</f:facet>
New York City (officially The City of New York) is the most
populous city in the United States, with its metropolitan area
ranking among the largest urban areas in the world.
</rich:accordionItem>
<rich:accordionItem>
<f:facet name="header">
<h:panelGrid columns="2">
<h:outputText value="other City" />
</h:panelGrid>
</f:facet>
New York City (officially The City of New York) is the most
populous city in the United States, with its metropolitan area
ranking among the largest urban areas in the world.
</rich:accordionItem>
</rich:accordion>
</rich:panel>
</h:form>
</h:body>
</ui:composition>